Following his recovery, Eudy returned in May 1990 as a member of Ric Flair's Four Horsemen,[3]
and he was billed by the ring announcers as being from "wherever he
damn well pleases". His first televised match back was a ten second loss
to Lex Luger
on Clash of the Champions in which the referee performed one of the
faster three counts in wrestling history. As one of the Horsemen, Eudy
feuded with Paul Orndorff and the Junkyard Dog. He attacked NWA World Heavyweight ChampionSting
following the champion's title match of the August 1990 Clash of the
Champions, setting up his first feud as a singles wrestler. At Halloween Havoc, a fake Sting (Barry Windham),
in collusion with Sid, let Sid pin him after switching places with the
real Sting in order for Sid to win the belt. However, they were thwarted
when the real Sting came out and beat Sid to retain the title.

Sid's association with the Horsemen became tenuous following this
episode, and he began a quasi-face run in November 1990 when he faced
The NightStalker on Clash of the Champions. Eudy won but was attacked post-match by the debuting Curtis Hughes. In response Sid recruited former partner Dan Spivey for a short-lived reunion of the Skyscrapers at Starrcade 1990, where the two defeated Mr. Hughes and The Motor City Madman. Following this match Eudy made an abrupt return to heel status, ending Trucker Norm's WCW run in January 1991 and memorably squashing Joey Maggs
in a Clash of the Champions later that month. He returned to full
fledged Horsemen activity and participated in the February War Games.
The Horsemen amicably split in April 1991, during which time he entered
negotiations with the WWF. Despite a huge contract offer and a promise
of a world championship run, Eudy announced his intentions to leave WCW.
Before departing he had a short feud with El Gigante that ended with his loss to the giant at SuperBrawl I.

Sid returned to active duty at the Royal Rumble,
emanating from Albany New York that year. This particular edition had a
special stipulation: the winner would win the vacant WWF Title, which
had been stripped from Hulk Hogan after two controversial title switches
in a row between Hulk and the Undertaker. Sid entered at #29, and was
among the final four wrestlers, along with Hulk Hogan, Randy Savage, and
Ric Flair, before he eliminated both Savage and then Hogan, leaving
himself and Flair in the ring. During the initial live pay-per-view
broadcast, this action was loudly cheered by the audience in attendance
even though, as per storyline plans, Sid "sneaked up from behind" to
throw Hogan out. The reaction is in retrospect widely believed to be due
to a combination of fans tiring of Hogan's all-American superhero
persona, and also responding positively to Sid's charisma. Nevertheless,
this reaction was edited out of future television replays as well as
the Coliseum home video release of the event; Play-by-play announcer Gorilla Monsoon
even re-recorded his voiceover commentary, now condemning Sid for his
actions when he previously said that Justice's elimination of Hogan was
fair. Hogan, who was still at ringside after being eliminated, grabbed
Sid's arm and distracted him long enough for Flair to eliminate him to
win the match and become the new WWF Champion. After the match, Sid and
Hogan got into an argument in the ring and had to be separated by
security. This incident began Sid's turn into a villain.

Less than a week later, on the January 25 episode of Superstars, WWF President Jack Tunney held a press conference to announce who among Sid, Savage, Hogan, "Rowdy" Roddy Piper and The Undertaker would face Ric Flair for the WWF Championship at WrestleMania VIII.
Before Tunney even announced who the number one contender would be, Sid
stood up as if Tunney called his name. Yet to Sid's annoyance, Tunney
chose Hogan. After the press conference, Sid referred to it as "the most
bogus act Jack Tunney has ever pulled off." Sid later issued an apology
to Hogan, which Hogan accepted. Sid and Hogan then teamed up to face
The Undertaker and Flair on the February 8 edition of Saturday Night's Main Event. During the match, after he double clotheslined
Undertaker and Flair, Hogan reached to Sid for a tag. However, Sid
refused to tag in and walked out of the match, completing his heel turn.
Despite this, Hogan won the match by disqualification.

On February 23 on an episode of Wrestling Challenge, Sid appeared as a guest on Brutus "The Barber" Beefcake's
"The Barber Shop". Knowing that Hulk Hogan (Beefcake's good friend) was
not in the arena, Sid attacked Beefcake and destroyed the Barber Shop
set with a chair. Later that night, it was announced that Hogan would
battle Sid (and not WWF Champion Ric Flair) at the main event of
WrestleMania VIII, resulting in Flair facing Randy Savage for the WWF
Title instead. A week later, Sid hired Harvey Whippleman
as his manager. Sid also began a post-match gimmick where he would
further "injure" his defeated opponents with one or more powerbombs (his
finishing move), and sometimes — after the defeated wrestler placed on a
stretcher — following this up by grabbing the stretcher and running it
into a fixture, such as a ringpost or guardrail.

At WrestleMania VIII, Sid lost his match to Hogan by disqualification when Papa Shango
interfered on Sid's behalf, allowing the two to double-team Hogan until
the returning Ultimate Warrior stormed the ring and saved Hogan. During
the match, Sid kicked out of Hogan's trademark Atomic Leg Drop;
according to popular belief, Charles Wright (who portrayed Papa Shango)
missed his cue to break up the pin attempt. During the match, Monsoon
referred to Sid as "Sycho Sid," a name that Eudy would use during his
later-1990s run in the WWF.

On a November 22, 2011 edition of Wrestling Observer Radio with Bryan
Alvarez, Dave Meltzer confirmed a story where Sid failed a drug test
prior to his Mania match with Hulk Hogan. He was allowed to do the match
and then went on their European tour. After the tour, he was told he
was going to serve his suspension, so Sid quit instead. His last
televised match was a defeat of Chris Walker. It has been said many times that he was trying to pursue a career in softball.[4]

During their United Kingdom tour in Blackburn, Lancashire on October 27, Eudy was involved in a hotel room scuffle with Arn Anderson
that resulted in both wrestlers stabbing each other with scissors. Both
were rushed to the hospital, as Anderson suffered scissor stab wounds
to the chest and stomach. Vicious stabbed Anderson twenty times, while
being stabbed four times himself.[1]
Sid was released from WCW after several wrestlers threatened to walk
out because of him. It had been planned to have Sid challenge then-World
Heavyweight Champion Vader at that year's Starrcade,
but Sid's departure removed him from this match and Ric Flair was
elevated to be the challenger against Vader. Based on WCW Worldwide
tapings that took place his departure, Sid would have defeated Vader and
become the new champion. In one event never aired on television at
these tapings, Sid placed the massive Vader in a torture rack.

On the February 20, 1995 episode of Monday Night Raw, Eudy returned to the WWF under the ring name Sycho Sid, where he became the bodyguard of Shawn Michaels. He, along with Jenny McCarthy, accompanied Michaels to ringside for Michaels' WWF Championship match against the champion and Michaels' former bodyguard, Diesel, at WrestleMania XI. Michaels had the match won after hitting his signature Sweet Chin Music, but Sid stood on the ring apron and distracted referee Earl Hebner,
allowing Diesel time to recover and pin Michaels after a Jackknife
Powerbomb to win the match and retain his title. The next night on Raw,
Michaels expressed dissatisfaction with Sid's interference and gave him
the night off for his rematch against Diesel at the first-ever In Your House
pay-per-view. In response, Sid replied to Shawn, "You don't give me the
night off!", and attacked Michaels from behind and powerbombed him
three times, turning Michaels into a face
again. Diesel came to Michaels' aid and clotheslined Sid over the top
rope. Michaels sustained a legitimate back injury as a result of the
attack and was sidelined for six weeks, thus taking him out of the title
bout.

On the November 13 episode of Raw, Sid faced the Intercontinental Champion Razor Ramon in a non-title match, with Ramon's friend The 1-2-3 Kid as the special guest referee. Razor was about deliver the Razor's Edge
on Sid, but The 1-2-3 Kid helped Sid avoid it, allowing Sid to pin
Ramon with a powerbomb after with the Kid making a fast count. After the
match, the Kid turned heel and joined the Million Dollar Corporation. In the first elimination match at Survivor Series, Sid and Corporation leader Ted DiBiase helped The 1-2-3 Kid pin Marty Jannetty
to win and become the sole survivor for his team. Later in the event,
Sid was randomly teamed up with his rival Shawn Michaels, Ahmed Johnson, and The British Bulldog to face Yokozuna, Owen Hart, Razor Ramon, and Dean Douglas
in a "Wild Card" Survivor Series Match. Sid was eliminated by Razor
Ramon after Michaels hit Sid with Sweet Chin Music. After his
elimination, Sid powerbombed Michaels. At In Your House 5: Season's Beatings,
Razor Ramon and Marty Jannetty defeated Sid and The 1-2-3 Kid. Sid and
The 1-2-3 Kid teamed up the next night to participate in the first-ever
Raw Bowl, which The Smoking Gunns won.

A severe injury sustained before or during a January 2, 1996 house show match in Hartford, Connecticut with Bob Holly led to Sid being taken off television.

Eudy would not be seen again until the July 8 episode of Raw,
when he was announced as the replacement of The Ultimate Warrior (who
had left the WWF) for the six-man tag team match, teaming with former
rival Shawn Michaels and Ahmed Johnson against Vader, Owen Hart, and The British Bulldog at the main event of In Your House 9: International Incident, effectively making him a face. However, Sid's team lost the match.

The next night on Raw, Sid started a feud with The British Bulldog. Sid faced the Bulldog at SummerSlam on August 18 and pinned Bulldog with the powerbomb, despite interference from Owen Hart. At In Your House 10: Mind Games on September 22, Shawn Michaels hit Mankind
with Sweet Chin Music and went for the pin to retain the WWF
Championship, but Vader came out, broke up the count, attacked Michaels,
and got Mankind disqualified. After the match, Mankind and Vader
double-teamed Michaels until Sid came out to make the save. He and Vader
fought their way backstage, starting a feud between the two.

Sid fought Vader at In Your House 11: Buried Alive
on October 20 in a match where the winner would face Shawn Michaels for
the WWF Championship at Survivor Series on November 17. As Sid was
about to powerbomb Vader, Vader's manager Jim Cornette
got on the ring apron to distract him. Michaels responded and pulled
Cornette off the apron before hitting him with Sweet Chin Music. Sid
then pinned Vader with a chokeslam
to win the match and to become the number one contender for the WWF
Championship. After the match, Sid celebrated his victory with Michaels.

At the 1996 edition of the Survivor Series, history repeated itself. Sid grabbed a camera from the cameraman and prepared to hit Michaels with it. Michaels' manager, Jose Lothario,
got on the ring apron and told Sid to put the camera down, but Sid
refused and hit Lothario in the chest with the camera instead. Although
this was the act of a heel, the audience cheered wildly for him and
booed Michaels, just as they had done, in Sid's favor, four and a half
years earlier against Hogan at the Royal Rumble. Sid dropped the camera
and as soon as he turned around, Michaels hit him with Sweet Chin Music;
however, Michaels went outside the ring to check on his manager instead
of going for the pin. Sid hit Michaels in the back with the camera,
then threw him back in the ring before hitting him with the powerbomb to
win the WWF Championship.

At In Your House 12: It's Time on December 15, Sid defended the title against Bret Hart
in a match where the winner would defend the title against Shawn
Michaels at the 1997 Royal Rumble on January 19. Hart made Sid tap out
to the Sharpshooter, but the referee was knocked out and unable to
witness the submission. As Shawn Michaels was commentating at ringside,
Sid and Hart left the ring and started fighting right beside him. After
Sid pushed Michaels then climbed into the ring with Hart, Michaels went
to hit Sid but Sid threw Hart into him. Sid then pinned Hart with the
powerbomb to retain the title.

At the Royal Rumble,
Sid defended the title against Michaels. During the match, Sid hit the
chokeslam on Michaels and repeatedly powerbombed him outside the ring.
Later on in the match, Jose Lothario got on the ring apron and Sid
approached him, but before he could do anything to Lothario, Michaels
hit Sid in the back and the face with the camera, knocking him out in
the process. Michaels went for the pin, but Sid managed to kick out.
Michaels then hit Sid with Sweet Chin Music to become the WWF Champion
for the second time. Michaels soon forfeited the title due to being
unable to wrestle, a claim still widely disputed by many during that
time, especially Bret Hart, who believe Michaels didn't want to drop the
title to him at Wrestlemania XIII. At In Your House: Final Four
in Chattanooga, a four-way title match was held for the vacant belt
between Bret Hart, the Undertaker, Vader, and Stone Cold Steve Austin.
Hart won, and was scheduled to face Sid the following night, on the
February 17, 1997 episode of Raw. During that match, Hart had Sid trapped in the Sharpshooter submission when Stone Cold Steve Austin,
whom Hart was feuding with, came to the outside of the ring and hit
Hart with a steel chair, allowing Sid to hit Hart with the powerbomb to
win the WWF Championship for the second time.

At WrestleMania 13 on March 23, Sid defended the title against The Undertaker. Hart interfered during the match, allowing The Undertaker to hit the Tombstone Piledriver
and pin Sid to become the WWF Champion for the second time. Following
WrestleMania, Sid was kept off of television until the May 12 episode of
Raw, where he returned as a face. He competed against Owen Hart and defeated him to become the partner of The Legion Of Doom in their feud with The Hart Foundation. At King of the Ring on June 8, Sid and The Legion Of Doom faced The Hart Foundation (Owen Hart, The British Bulldog, and Jim Neidhart)
in a six-man tag team match, which The Hart Foundation won when Owen
pinned Sid with a roll-up. On June 9, Sid made his final appearance in a
victorious effort against Owen Hart on Raw before leaving the WWF once again.

At the behest of his real life friends Kevin Nash and Scott Hall, Eudy returned to WCW in mid-1999, joining Randy Savage's heelstableTeam Madness. Upon his return, he took the nickname of "The Millennium Man," shortly after Chris Jericho's "Millennium Man" gimmick debuted in the WWF. WCW even released a home video highlighting Sid's return to WCW called Sid Vicious: Millennium Man. Additionally, Sid was dubbed as undefeated, having a winning streak much like Goldberg
had previously; although, the majority of this streak was due to Sid
coming to the ring and attacking wrestlers already in a match or
immediately following their match and thus "defeating" them. On
September 12, 1999, Sid won his first and only US Heavyweight title from Chris Benoit at Fall Brawl. He then began a feud with Goldberg who challenged him for the US Title at Halloween Havoc.
Earlier that night, however, their backstage fighting led Sid to
require stitches, though he refused to be treated, which led to Sid
bleeding openly the entire night. After brawling with Goldberg, a weary
Sid lost the bout due to excessive bleeding, awarding Goldberg the US
Championship against his opponent's will. Sid lost again to Goldberg in
an "I Quit" match at Mayhem, effectively ending their feud and Sid's "streak."

After the "Millennium Man" gimmick ran dry, Sid became a face and started to contend for the World Heavyweight Championship. He was placed in a match at Souled Out
in January to fill the suddenly vacant title after Bret Hart was forced
to relinquish it due to a concussion. Sid would lose the match to Chris
Benoit, but the title was again vacated as Benoit left for the WWF the
next day. The onscreen explanation was that Sid's foot was under the
rope during his submission loss. The next week, Sid was presented with a
challenge by Nash, who had become commissioner of WCW. If he could beat
Don and Ron Harris in a match on Monday Nitro
that night, he would face Nash for the championship that night. Sid
managed to defeat the Harris Brothers and eventually Nash himself to win
the World Heavyweight Championship. Two nights later on Thunder, Nash stripped Sid of the championship due to him not beating the legal Harris brother in the match on Nitro. A rematch between Sid and Nash was set up, but Sid again defeated Nash on Nitro to win the title for a second time. He later successfully defended the title at SuperBrawl 2000 in a three-way match against Scott Hall and Jeff Jarrett.

On March 19, Sid defended his title against Jeff Jarrett thanks in part to help from a returning Hulk Hogan, which set up a match for the following night's Nitro pitting Sid and Hogan vs. Jarrett and Scott Steiner.
During the course of the match, Sid turned heel and attacked Hogan, due
to his being incensed that the fans were chanting Hogan's name. He
chokeslammed Hogan and forced the referee to count Hogan being pinned,
although the official result was a no contest. This apparently might
have been to set up a match for the upcoming Spring Stampede pay-per-view in April. However, shortly after this, WCW began its New Blood
angle and Sid (along with all the other WCW champions at the time) was
stripped of his championship. He did not play a large role in the angle
that followed, and was kept off of television for several months. He
returned late in the year as a challenger for Scott Steiner's World
Heavyweight Championship, but Sid failed to defeat Steiner in their
title match at Starrcade.

On January 14, 2001 at the Sin pay-per-view, Sid faced Steiner, Jarrett, and Road Warrior Animal in a Four Corners match for the WCW Championship. During the bout, however, he suffered a near career-ending injury.[3]

Members of WCW management allegedly felt that Eudy needed to broaden
his arsenal of wrestling moves and suggested that he try an aerial
maneuver, despite his "unwillingness." Eudy felt it unnecessary for a
wrestler of his size and type to do high spots, and didn't feel
comfortable doing them. During the match, Eudy suffered a leg fracture following his leap from the second turnbuckle in an attempted big boot
on Steiner. This had him awkwardly landing on one foot while kicking
with the other, severely fracturing the leg he landed on. Eudy broke his
left leg in half, snapping both the tibia and fibula, with at least one of the bones breaking through the skin.[5] The fracture was too graphic for many TV stations to re-air,[5] although it was shown on the following Nitro.

The injury put Sid out of action indefinitely, and he pondered retiring from wrestling for good.

"I had about a year left on my contract, and I was thinking back
then prior to hurting my leg what was I going to do as far as wrapping
up my career. The only thing I really wanted to do was ideally go out in
a big pay-per-view, like a WrestleMania or something like that main event, leave like that, and not come back again. It would really be the retirement match."[6]

A 17-inch (43 cm) rod was placed in his leg during the two-hour
surgery. For a while, Eudy used a cane to walk. Sid later sued WCW,
claiming that he was made to jump off the second rope against his
objections.[6] The injury forced a plot change in the 2001 SuperBrawl Revenge event. The main event was supposed to be Kevin Nash, Diamond Dallas Page,
and Sid against Scott Steiner, Jeff Jarrett, and Road Warrior Animal
but was rewritten as Kevin Nash vs. Scott Steiner. WCW would then be purchased by the WWF the following month, ceasing any possibility of Sid's return to the company after rehabilitation.